A motherboard, also known as the mainboard or system board, is the main printed circuit board (PCB) found in computers and other expandable systems. It holds many of the electronic components of the system, such as the central processing unit (CPU) and memory, and provides connectors for other peripherals. Unlike a backplane, a motherboard includes significant sub-system electronics such as the processor and other components. In addition to the CPU and memory, the motherboard may include a PCB with expansion capabilities, such as includes sound cards, video cards, network cards, hard drives, or other forms of storage, TV tuner cards, cards providing extra USB or FireWire slots and a variety of other custom components. To provide expansion capability for such cards, one or more expansion buses having expansion connectors are provided with the motherboard. For many users, however, more functionality is often needed from the motherboard expansion buses than usually available from the manufacturer.